Skip to main content

What You Should Know About BCAAs

Guest Blog Post by Leanne Ray, MS, RDN


Branched-chain amino acids seem to be all the rage in the nutrition world – specifically in regards to performance nutrition – but what does the science actually say? And should we be supplementing to optimize our time at the gym?

branched chain amino acids

What are Branched-Chain Amino Acids?

Amino acids are known as the building blocks of proteins. There are 20 amino acids, nine of which are essential. This means that the body cannot produce them on it’s own and they must be consumed through food. The nine essential amino acids are: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.

Leucine, isoleucine, and valine are called branched-chain amino acids (BCAAs) because their structure includes (you guessed it) a side chain. (Flaxseed contains all three BCAAs! Read more about it below).

BCAAs are unique because they are broken down in muscle rather than the liver like most amino acids. Because of this, they may play a role in energy production during exercise.

Leucine, specifically, is a precursor for muscle synthesis and may also play a role in protein synthesis.


What Does Science Say?

Exercise increases an individual’s need for BCAAs. Therefore, incorporating them in your diet may be beneficial for optimal post-exercise muscle recovery.

BCAAs, especially leucine, may help to increase muscle size and strength when used in conjunction with a structured and consistent strength training program. Some studies suggest that BCAAs may help reduce muscle soreness and fatigue during exercise. There is also some research suggesting that BCAAs may enhance the effect of a high protein meal.

Evidence is limited in regards to improvements on endurance exercise.


Where Can I Find BCAAs?

Animal foods, such as eggs and fish, are excellent sources of BCAAs. Plant based sources include: soy, sunflower seeds, and ground flaxseed. Flaxseed contains all three BCAAs in small amounts. It contains about 3 grams of BCAAs per 100 grams of flax, including 1.24 grams of leucine, 0.90 grams of isoleucine, and 1.07 grams of valine. A serving of flax can be easily incorporated into meals like smoothies and oatmeal (or try these Peanut Butter Flaxseed Energy Bites!)

You could also consume BCAAs in supplement form. However, this is generally considered unnecessary unless you have above average needs. Additionally, the extra cost you spend on a supplement could instead be put towards health-promoting whole foods.

The Bottom Line

A nutritious and varied diet can easily provide the minimum BCAA requirement for most people, especially recreational exercisers. Try eggs, fish, and ground flaxseed!

All essential amino acids are important components of a healthful diet which is why consuming a variety of protein sources (from both animal and plant sources) along with a consistent strength training routine is your best bet for building and retaining muscle.

If you choose to purchase BCAAs in supplement form, keep in mind that supplements are not regulated by the Food and Drug Administration (FDA) in the same way that medications are. It’s important to choose high-quality, third-party tested options if you choose to purchase a supplement. It’s always a good idea to consult with a registered dietitian or other medical provider before incorporating a supplement into your nutrition plan.




About the Author

Leanne Ray, MS, RDN is the owner of Leanne Ray Nutrition, where she offers 1:1 virtual health/wellness coaching, in-person cooking events, along with nutrition writing, and recipe development services. Check out her food blog for simple, plant-powered recipes that even the busiest of people can manage in addition to relatable, science-based articles. Find her on Instagram at @LeanneRayRDN and on Facebook at Leanne Ray, MS, RDN.



National Institutes of Health Office of Dietary Supplements. Dietary Supplements for Exercise and Athletic Performance. Retrieved from on 9/10/2018.

National Institutes of Health. MedLine Plus. Amino Acids. Retrieved from on 9/10/2018.

Wolfe RR. Branched-chain amino acids and muscle protein synthesis in humans: myth or reality? J Int Soc Sports Nutr. 2017;14:30. Retrieved from on 9/10/2018.

USDA Nutrient Database. Retrieved from on 9/10/2018.

Shimomura Y, Yamamoto Y, Bajotto G, Sato J, Murakami T, Shimomura N, Kobayashi H and Mawatari K. Nutraceutical effects of branched-chain amino acids on skeletal muscle. J Nutr. 2006; 136(2):529S-532S.Retrieved from on 9/10/2018.


Related News

The Skinny on Fat – What You Should Know

What are Phytoestrogens?